There are many C4D tutorials under ePMV general tutorials and AMI newsletter tutorials.
You can also download long introductory tutorials as workshop PDF files from the main tutorials page.
We'll reorganize and link everything or filter them soon.
Goodsell molecular style rendering: Excellent descriptive tutorial from Dr. Bonnie Scott of SnareMedia showing how to generate a Goodsell-like non-photorealistic rendering of individual molecules using three approaches including Chimera/Photoshop and ePMV (detailed in the host Cinema 4D). Available as a vimeo video tutorial and as text. No video yet for the ePMV part as of May 17, 2012.